Technology Field
The present invention relates to a memory management method and more particularly, to a memory management method, a memory control circuit unit and a memory storage device for a rewritable non-volatile memory module.
Description of Related Art
The markets of digital cameras, cellular phones, and MP3 players have expanded rapidly in recent years, resulting in escalated demand for storage media by consumers. Due to having characteristics, such as data non-volatility, low power consumption, compact size and no mechanical structure, the rewritable non-volatile memory module (e.g., a flash memory) is suitable for being built in the aforementioned portable multi-media devices listed for example.
Generally, in the management of physical erasing units in the re-writable non-volatile memory module, a memory management circuit only records the same single information for representing situations of bad physical programming units in all the physical erasing units. The memory management circuit also determines good physical erasing units of the rewritable non-volatile memory module according to the recorded single information. However, address offset values of different physical programming units in each physical erasing unit may be different. As a result, correct information with respect to the bad physical programming units in each physical erasing unit cannot actually be obtained if only the single information is employed for representing the situations of the bad physical programming units in each physical erasing unit. Moreover, the memory management performed through recording only the single information means that even in actual use, the address offset values corresponding to the bad physical programming units in each good physical erasing unit have to be the same. In this way, some available physical erasing units may be determined as bad physical erasing units and become unusable, which results in only less available capacity of the rewritable non-volatile memory module being determined. Meanwhile, in a system that at least two good physical erasing units are configured as a super physical unit, the address offset value corresponding to the bad physical programming units in each good physical erasing unit have to be the same, which leads to reduction in the number of the super physical units. Accordingly, how to reliably record correct information with respect to the bad physical programming units in each physical erasing unit so as to determine more capacity available for use is an important issue concerned by technicians of the field.